Preheat oven to 160°C/320°F. Butter the bread slices, spread half with marmalade and sandwich with remaining slices.
Cut in half and arrange in two 3 cup-capacity (720ml) ovenproof dishes. Place the milk, cream, eggs, caster sugar and vanilla extract in a bowl and whisk well. Pour over the bread. Allow to soak for 1–2 minutes. Sprinkle over the demerara sugar and place in a large deep baking dish. Add enough boiling water to come halfway up the sides of the dishes.
Bake for 1 hour 5 minutes or until just set. Serve with custard or cream.

I made bread pudding for the first time very recently too and I got immediately addicted. I keep asking myself why I did not try it earlier! Yours look so delicious...marmelade and butter...perfect for breakfast!